Rotary air cushion transporter

ABSTRACT

A low profile rotary transporter having a turntable supported by a plurality of air bearings. A separate tubular platform section underlying each air bearing and having a supply portion for carrying air under pressure from a supply line to the air bearing and a damping portion communicating with the air bearing. Each air bearing and its associated platform are fixedly mounted on a ground surface and the turntable is removably mounted on a positioning rod in the ground surface.

United States Patent [1 1 Burdick et a1.

1 1 ROTARY AIR CUSHION TRANSPORTER [75] Inventors: Robert E. Burdick; Baxter K. Wolf,

both of Santa Barbara, Calif,

[73] Assignee: Rolair Systems, Inc., Santa Barbara,

Calif.

[22] Filed: Dec. 7, 1972 [21] Appl. No.: 313,147

[52] US. Cl 108/139, 104/46, 248/349 [51] Int. Cl A471) 11/00 [58] Field of Search 108/139, 102, 104; 104/37,

[56] References Cited UNITED STATES PATENTS 2,395,528 2/1946 Andersen 104/46 2,536,937 1/1951 Hosea i 108/104 3,103,364 9/1963 Macks et a1. 248/349 [451 July 9,1974

3,332,656 7/1967 Johnson et a1 108/139 Primary Examiner-Bobby R. Gay Assistant Examiner-Darrell Marquette Attorney, Agent, or FirmI-larris, Kern, Wallen & Tinsley ABSTRACT A low profile rotary transporter having a turntable supported by a plurality of air bearings. A separate tubular platform section underlying each air bearing and having a supply portion for carrying air under pressure from a supply line to the air bearing and a damping portion communicating with the air bearing. Each air bearing and its associated platform are fixedly mounted on a ground surface and the turntable is removably mounted on a positioning rod in the ground surface.

4 Claims, 4 Drawing Figures PATENTEBJUL 91m SHEU 1 (IF 2 1 ROTARY AIR CUSHION TRANSPORTER This invention relates generally to air cushion transporter devices, and more particularly to a low profile rotary transporter wherein a turntable positioned on a central rod is rotatable on a plurality of circumferentially spaced air bearings fixedly attached to a ground surface.

Typical examples of low profile transporters incorporating inflatable air bearings are shown in the copending application of Robert E. Burdick entitled Re placeable Air Cushion Device, Ser. No. 180,666, filed Sept. 15, 1971, and the co-pending application of Robert E. Burdick and Baxter K. Wolf entitled Transporter With Built-In Distribution and Damping, Ser. No. 298,464, filed Oct. 18, 1972. Compressed air is delivered to the air bearings which generate a film of air between the transporter and the ground surface resulting in very low friction between the transporter and the ground.

However, the low profile air cushion transporters with which we are familiar are not suited for use as rotary transporters providing rotation about a predetermined central reference point. Accordingly, it isan object of the present invention to provide an easily installed rotary transporter unit having such thin profile, off center load capability, and avoidance of pockets between the corners of a conventional rectangular transporter, and the resultant exposure of the operating surface to debris and damage. Another object is to provide a removable turntable mounted over a plurality of fixed air bearings which generate a film of air against the bottom surface of the turntable. Such installation is particularly suited to a concrete floor having a work surface of wood blocks or the like so that when a portion of the work surface is removed, the rotary transport unit can be mounted directly on the concrete subfloor with the top surface of the turntable approximately level with the surrounding work surface when the air bearings are deflated.

A further object is to provide a modular-type unit which can be completely installed on a concrete floor having an anchor bolt for each air bearing, a turntable positioning rod, and an air supply line channel.

More specifically, it is an object of the present invention to provide each air bearing with an underlying platform having tubes for supporting the air bearing as well as providing an air supply tank and a damping tank or chamber. Other objects, advantages, features and results will more fully appear in the course of the following description.

IN THE DRAWING:

FIG. 1 is a top view of a rotary air cushion transporter incorporating a presently preferred embodiment of the invention;

FIG. 2 is an enlarged partial view of FIG. 1 showing portions cut away;

FIG. 3 is an enlarged sectional view taken along the line 3-3 of FIG. 1 with the air bearings deflated; and

FIG. 4 is an enlarged partial sectional view taken along the line 4-4 of FIG. 2 with the air bearings inflated.

In the embodiment illustrated, the rotary transporter comprises a turntable 9, a platform '10 and eight conventional replaceable air bearings 11. Each air bearing comprises a lower relatively rigid plate 12, typically of steel, and an upper flexible diaphragm l3, typically of rubber, with the diaphragm clamped to the plate at the periphery by a ring 14 and at the center by a disc 15 secured by rivets 16 to produce an annular space 17 be tween the diaphragm and plate and a central space 18 between the diaphragm and the turntable 9. Openings 19 in the diaphragm 13 provide air flow paths between the annular space 17 and central space 18. Openings 20 and 21 in the plate 12 are aligned with openings in the platform when the bearing is mounted on the platform for air flow between the bearing and the platform.

The platform 10 is formed of a plurality of pieces of rectangular steel tube welded together side by side, with appropriate end plates. The platform is formed with standard mill run shapes requiring only cutting to appropriate length and providing openings for air passages and mounting bolts in selected locations. The platform 10 in the exemplary form includes substantially identical sections associated with each separate air bearing 11. The sections are positioned at equal radial distances from the center of the turntable 9 and are displaced circumferentially from each other with the pieces of steel tube of each section normal to the radial direction of the turntable.

Each platform section has a supply tank portion formed of a tube closed by end plates 31. Air supply lines 32 connect adjacent tubes 30 together through openings in the end plates to provide communication between a central air supply line 33 and the supply tank portion of the platform. A duct 34 is provided in the top of the tube 30 such that when the rotary transporter is assembled and installed as described hereinafter, the duct 34 aligns with the opening 20 in the plate 12. Thus, a valve 35 in the central air supply line 33 provides for control of air flow into all of the air bearings.

. cation between the three tubes to obtain the desired total volume. Duct 41 in the top of the tube 37 aligns with opening 21 in the plate 12 to provide communication with the air bearing thereabove.

With respect to assembly and installation, the rotary transporter has a vertical thickness sufficiently small so that installation on a concrete floor 42 having an overlying work surface 43 such as wooden blocks or the like (typically two inches thick) enables the top of the turntable 9 to be approximately level with the top of the work surface when the air bearings are deflated. To achieve this, a portion of the work surface 43 is removed and a ring or circular angle 44 is installed flush with the adjacent work surface 43 by bolts 45 secured to anchors 46 in the concrete 42. A channel or the like may be provided in the concrete 42 to allow the central air supply line to pass underneath the angle 44. A vertical positioning rod 47 is installed in the concrete 42 at the center of the circle defined by the angle 44. Each section of the platform 10 and its associated air bearing 11 are installed inside the angle 44 in circumferentially spaced positions a predetermined radial distance from rod 47 by a bolt 48 secured to an anchor 49 in the concrete 42. The platform 10 may include an angle 49a welded to the tube 30 to provide additional support to the overlying air bearing 11.

The turntable 9 has a flat upper surface and includes a central opening for receiving the positioning rod 47, four handling holes 50 and vertical support bars such as concentric bars 51 and angles 52 on its underside. When the turntable 9 is placed inside the circular angle 44 and over the positioning rod 47 while the air bearings 11 are deflated, the vertical support bars 51, 52 rest against the concrete 42 (See FIG. 3). The diameter of the turntable 9 is less than the diameter of the circular angle 44 to prevent frictional contact therebetween.

In actual operation, a load is moved from the work surface 43 to the top of the turntable 9. An air line is connected at the valve 35 and the valve is opened. Air under pressure flows through the air lines 32, 33 into the tube 30 and then to each of the air bearings through the aligned ducts 34 and openings 20. At each air bearing air flows into the annular space 17 and from there into the damping chamber and into the central space. The air flow inflates the diaphragm of the air bearing to the position shown in FIG. 4, raising the turntable and the support bars 51, 52. Air flows from the central space 18 outward between the diaphragm and the bottom surface of the turntable providing a thin film of air on which the turntable rests. The turntable and its load are now ready for rotation about the positioning rod 47 and over the concrete with the very low friction resulting from the air film.

When the turntable is rotated to the desired position, the air supply is shut off, the air bearings are deflated and the turntable moves downward to rest on the bars 51, 52.

The invention therefore provides a low profile rotary air cushion transporter with no air distribution piping other than the air supply lines, with all of the necessary air lines being provided by the tubes which also provide the mechanical support structure under the air bearings. Furthermore, the modular-type rotary transporter of the invention can be easily installed by providing a concrete floor with an anchor bolt for each air bearing, a center turntable rod, and an air line channel. In one instance, a six-foot diameter turntable having a total height of only two inches will handle a 12,000 pound load whose center-of gravity may be at any point within a three-foot diameter circle.

Although an exemplary embodiment of the invention has been disclosed and discussed, it will be understood that other applications of the invention are possible and that the embodiment disclosed may be subjected to various changes, modifications and substitutions without necessarily departing from the spirit of the invention.

We claim as our invention:

1. A rotary air cushion transporter comprising:

a plurality of air bearings;

platform means communicating with said air bearings for carrying air under pressure;

means attached to said air bearings and said platform means for fixedly mounting them on a ground sur face with said air bearings circumferentially displaced relative to a central reference point and overlying said platform means;

air supply means connected to said platform means for providing air under pressure; a turntable overlying said air bearings; and positioning means engaging said turntable for allowing said turntable to rotate about said central reference point when said air bearings are inflated;

said platform means including a supply tank portion for carrying air under pressure to said air bearings, and a damping tank portion communicating with said air bearings.

2. The transporter of claim 1 wherein said platform means includes a separate section associated with each of said air bearings, said separate section including a supply tank portion and a damping tank portion.

3. The transporter of claim 2 wherein said damping tank portion includes a plurality of tubes attached together and having aligned openings for communication therebetween.

4. The transporter of claim 1 wherein said turntable includes vertical bar means for supporting said turntable on said ground surface when said air bearings are deflated. 

1. A rotary air cushion transporter comprising: a plurality of air bearings; platform means communicating with said air bearings for carrying air under pressure; means attached to said air bearings and said platform means for fixedly mounting them on a ground surface with said air bearings circumferentially displaced relative to a central reference point and overlying said platform means; air supply means connected to said platform means for providing air under pressure; a turntable overlying said air bearings; and positioning means engaging said turntable for allowing said turntable to rotate about said central reference point when said air bearings are inflated; said platform means including a supply tank portion for carrying air under pressure to said air bearings, and a damping tank portion communicating with said air bearings.
 2. The transporter of claim 1 wherein said platform means includes a separate section associated with each of said air bearings, said separate section including a supply tank portion and a damping tank portion.
 3. The transporter of claim 2 wherein said damping tank portion includes a plurality of tubes attached together and having aligned openings for communication therebetween.
 4. The transporter of claim 1 wherein said turntable includes vertical bar Means for supporting said turntable on said ground surface when said air bearings are deflated. 